Texture

I am fascinated by the patterns found in nature. This is a slab of rock with a thin layer of water running over it. It had been laid to provide a lasting surface on a track where a stream crossed. 
It has been bright and sunny today but the wind has been strong and bitterly cold so not a day to venture out for too long. 
I had to correct my self assessment tax return today. I had been trying to understand the final assessment and seeking guidance from HMRC (in vain - they provided numerous obscure red-herrings.) Once I had discovered my error by comparing it with last year's return problem solved. Once I increased my income amount, my tax went from owing income tax to gaining a refund. There must be a lesson there somewhere?